Air-fired CO2 capture ready circulating fluidized bed heat generation with a reactor subsystem

Abstract

A combustor 110 combust a fluidized bed of fossil fuel 114, 114′ to heat a working fluid 102 and generate flue gas 104. An air preheater 144 has first and second gas passageways 144a, 144b for respectively directing the generated flue gas 150 and another gas 250 with captured CO2 generated by combustion outside of the combustor 110. When operated in a non-CO2 capture, the air preheater 144 receives the flue gas 150, but not the other gas 250, and the first gas passageway 144a directs the flue gas 150 so as to preheat the air 188. However, when operated in the CO2 capture mode, the air preheater 144 receives the flue gas 150 and the other gas 250, and the second gas passageway 144b also directs the other gas 250 so as to preheat the air 188′. In either mode, the preheated air 188, 188′ is applied by the combustor 110 to fluidize a bed of fossil fuel 114, 114′.

Description

RELATED APPLICATIONS[0001]The present invention claims benefit of U.S. Provisional Patent Application Ser. No. 61 / 031,764, entitled “AIR-FIRED CO2 CAPTURE READY CIRCULATING FLUIDIZED BED HEAT GENERATION”, and U.S. Provisional Patent Application Ser. No. 61 / 031,761, entitled “AIR-FIRED CO2 CAPTURE READY CIRCULATING FLUIDIZED BED HEAT GENERATION WITH A REACTOR SUBSYSTEM”, which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION[0002]The present invention relates generally to heat generation. More particularly, the present invention relates to air-fired CO2 capture ready fluidized bed heat generation. The invention is particularly suitable for designing air fired circulating fluidized bed heat generating systems for subsequent CO2 capture.BACKGROUND OF THE INVENTION[0003]Heat generating systems with furnaces for combusting fossil fuels have long been employed to generate controlled heat, with the objective of doing useful work. The work might be in the form o...

AI Technical Summary

Benefits of technology

The invention is a heat generating system that can operate in either a non-CO2 capture mode or a CO2 capture mode. The system includes a combustor that combusts a fluidized bed of fossil fuel to heat a working fluid and generate flue gas. The system also includes a preheater that preheats air by directing the flue gas to the first passageway. The system can also include a separator to separate the entrained solids from the flue gas and a heat exchanger to transfer heat from the solids to cool them. In the CO2 capture mode, the system also includes a reactor for combusting the separated solids to generate the other gas. The technical effects of the invention include improved energy efficiency and reduced emissions of CO2 from the heat generating system.

Problems solved by technology

However, while the disclosed technique can be used to significantly reduce CO2 emissions, there remains a reluctance in many quarters to add coal fired heat generating system capacity because of concerns regarding the future governmental regulation CO2 emissions and the costs of meeting these regulations.

Furthermore, particularly in retrofit situations, the system site itself may be insufficient to accommodate an architecture of the type described in the '567 patent.

Thus, while there is a recognized need for more heat generating system capacity to, for example, produce additional electrical power, and it is also recognized that CFB coal fired systems are an efficient means to generate such heat, the ongoing debate over global warming, and the increasing attention being given to CO2 emissions from the burning of fossil fuels such as coal, and most particularly the cost of capturing CO2 in terms of both capital expense and reduced energy production, have undoubtedly delayed some if not many installations, which could increase capacity and thereby increase the availability of power to the nation and the world.

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